Table 1: Cross-correlation coefficients and the corresponding time lags for the entire period (1996–2011).

IndicesCorrelation coefficients ( )
(95% significance level)
Time lags (months)

Sunspot number −0.91 ± 0.01+14
Coronal mass ejections index −0.84 ± 0.010
Interplanetary magnetic field IMF−0.86 ± 0.01+1
Heliospheric current sheet HCS−0.82 ± 0.01+8